Double Glazing Cost: What You'll Pay Per Window

Double glazing cost per window is one of those figures that gets quoted as a single number online far more often than it should be — the real price depends on frame material, window size, and installation complexity, not just the glass itself.

Typical UK double glazing costs per window

These are general, indicative supply-and-fit ranges for a standard-sized double-glazed window — actual cost varies with size and frame material.

• uPVC frame: roughly £400–£800 per window
• Timber (softwood) frame: roughly £700–£1,200 per window
• Timber (hardwood) or aluminium frame: roughly £900–£1,600 per window

See our full window replacement cost guide for the wider picture, including a whole-house worked example and what to check before choosing an installer.

A worked example: one room vs. a whole house

Replacing a single standard uPVC window in one room typically costs towards the higher end of the £400–£800 range, since there's no shared cost across multiple units. Replacing 4–5 windows on one side of the house (say, a full upstairs) usually brings the effective per-window cost down somewhat, and a whole-house job of 10+ windows benefits the most from shared scaffolding, access and site-visit costs.

What actually affects the per-window price

Frame material

The single biggest factor — uPVC is consistently the most budget-friendly option; timber and aluminium cost more both upfront and, in timber's case, in ongoing maintenance.

Window size and shape

A standard rectangular window of average size sits within the ranges above. Large picture windows, bay windows, and non-standard shapes (arched tops, unusual angles) cost meaningfully more due to the bespoke glazing and frame work involved.

Glazing specification

Standard double glazing sits within the ranges above; low-emissivity coatings, enhanced acoustic glazing, or upgrading to triple glazing all add cost on top.

Installation complexity

Ground-floor windows with easy access cost less to install than upper-floor windows needing scaffolding, or windows in a hard-to-reach part of the property.

Double glazing vs. secondary glazing

Where a full window replacement isn't wanted or possible — a listed building, for example, where the original frames must be retained — secondary glazing (an additional internal pane fitted inside the existing window) is a genuinely different, usually cheaper option that improves both thermal and acoustic performance without replacing the original window. It's a different product solving a similar problem, worth knowing about specifically for period or listed properties where standard double glazing replacement isn't an option.

Maintenance costs over time

uPVC frames need minimal ongoing maintenance beyond occasional cleaning. Timber frames need periodic repainting or re-staining — a genuine ongoing cost that's worth factoring in alongside the higher upfront price, not just comparing the initial quote in isolation. Aluminium sits between the two, needing very little maintenance but carrying a higher upfront cost than uPVC.

Getting an accurate figure

Because size and shape vary so much between individual windows in a real house, the only reliable way to get an accurate cost is a proper survey of each window being replaced — a single per-window average, while useful for early budgeting, will always be less accurate than a room-by-room, window-by-window quote.